1. Field of the Invention
The present invention relates to an information providing apparatus that provides service information over a wireless network, a wireless terminal that receive service information provided from an information providing apparatus and a wireless network system.
2. Description of the Related Art
In recent years, services have made their appearance that provide various kinds of service information to users who use a wireless terminal. For example, at an installation, advertisement information may be provided to a wireless terminal used by a specific user who uses the installation. Another service makes its appearance that provides service information requested by a user through a wireless terminal. For example, in a case where a user requests general guidance information of an installation by using a wireless terminal, the general guidance information of the installation may be provided to the wireless terminal used by the user.
A factor responsible for the prevention of the use of the services may be a risk of the leak of information relating to a user who uses the wireless terminal. In a case where information is exchanged over a wireless network, a third party can listen in to the exchanged information easily. Therefore, information such as an address of the wireless terminal used by a user may leak easily. In a case where the wireless network is a multi-hop network that relays the information to be exchanged through one or more relays, information such as an address of the wireless terminal used by a user may leak through an illegal relay.
JP-Kohyo (translation of PCT) No. 2003-516035 (Patent Document 1) discloses a system that transmits information to a terminal with multiple identification names or indicators such as an address. The identification name or indicator indicating a terminal is described as a Bloom Filter created from the identification names or indicators. In this case, an identification name or indicator indicating a terminal, such as an address of the terminal, may not be obtained from the Bloom Filter describing an identification name or indicator indicating the terminal. Therefore, the leak of information such as an address of the terminal to a third party can be prevented.